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892. Miniature excitatory synaptic ion currents in the earthworm Lumbricus terrestris body wall muscles
- Creator:
- Volkov, E. M., Nurullin, L. F., Nikolsky, E., and Vyskočil, F.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Biochemie. Molekulární biologie. Biofyzika, biochemie, acetylcholin, ionty, svalové buňky, žížaly, biochemistry, acetylcholine, ions, muscle cells, earthworms, 2, and 577
- Language:
- English
- Description:
- The miniature excitatory postsynaptic currents (MEPCs) of the muscle cells of the earthworm Lumbricus terrestris were recorded by glass microelectrodes. In a single synaptic zone, three types of MEPC were recorded: a fast single-exponential type that decayed with τ=0.9 ms, a slow single-exponential with τ=9.2 ms and a two-exponential MEPC with τ = 1.3 and 8.5 ms, respectively. The muscle cells of earthworms contain populations of yet-unidentified ionic channels that might be different from the common nicotinic and muscarinic groups of acetylcholine receptors, since these MEPCs are not sensitive to d-tubocurarine, atropine, benzohexonium or proserine. Alternatively, besides ACh receptors, the membrane may contain receptors for an other yet-unidentified excitatory transmitter., E. M. Volkov, L. F. Nurullin, E. Nikolsky, F. Vyskočil., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
893. Místa, kde pracují ekologové: velké mezery na mapě světa
- Creator:
- Jan Plesník
- Format:
- Type:
- article, zprávy, model:article, and TEXT
- Subject:
- Obecná botanika, ekologie, ekologický výzkum, 2, and 581
- Language:
- Czech
- Description:
- Jan Plesník.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
894. Modelling photosynthesis in shallow algal production ponds
- Creator:
- Ritchie, R. J. and Larkum, A. W. D.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, algal production ponds, Chlorella, Dunaliella, electron transport rate, light saturation curves, Phaeodactylum, photoinhibition, photosynthesis, photosynthesis vs. depth, primary productivity, pulse amplitude modulation fluorometry, 2, and 58
- Language:
- Multiple languages
- Description:
- a1_Shallow ponds with rapidly photosynthesising cyanobacteria or eukaryotic algae are used for growing biotechnology feedstock and have been proposed for biofuel production but a credible model to predict the productivity of a column of phytoplankton in such ponds is lacking. Oxygen electrodes and Pulse Amplitude Modulation (PAM) fluorometer technology were used to measure gross photosynthesis (PG) vs. irradiance (E) curves (PG vs. E curves) in Chlorella (chlorophyta), Dunaliella salina (chlorophyta) and Phaeodactylum (bacillariophyta). PG vs. E curves were fitted to the waiting-in-line function [PG = (PGmax × E/Eopt) × exp(1 — E/Eopt)]. Attenuation of incident light with depth could then be used to model PG vs. E curves to describe PG vs. depth in pond cultures of uniformly distributed planktonic algae. Respiratory data (by O2-electrode) allowed net photosynthesis (PN) of algal ponds to be modelled with depth. Photoinhibition of photosynthesis at the pond surface reduced PN of the water column. Calculated optimum depths for the algal ponds were: Phaeodactylum, 63 mm; Dunaliella, 71 mm and Chlorella, 87 mm. Irradiance at this depth is ≈ 5 to 10 μmol m-2 s-1 photosynthetic photon flux density (PPFD). This knowledge can then be used to optimise the pond depth. The total net P N [μmol(O2) m-2 s-1] were: Chlorella, ≈ 12.6 ± 0.76; Dunaliella, ≈ 6.5 ± 0.41; Phaeodactylum ≈ 6.1 ± 0.35. Snell’s and Fresnel’s laws were used to correct irradiance for reflection and refraction and thus estimate the time course of PN over the course of a day taking into account respiration during the day and at night. The optimum PN of a pond adjusted to be of optimal depth (0.1-0.5 m) should be approximately constant because increasing the cell density will proportionally reduce the optimum depth of the pond and vice versa., a2_Net photosynthesis for an optimised pond located at the tropic of Cancer would be [in t(C) ha-1 y-1]: Chlorella, ≈ 14.1 ± 0.66; Dunaliella, ≈ 5.48 ± 0.39; Phaeodactylum, ≈ 6.58 ± 0.42 but such calculations do not take weather, such as cloud cover, and temperature, into account., R. J. Ritchie, A. W. D. Larkum., and Obsahuje bibliografii a dodatky
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
895. Modulated increased UV-B radiation affects crop growth and grain yield and quality of maize in the field
- Creator:
- Yin, L. N. and Wang, S. W.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, growth, maize, quality, UV-B radiation, yield, 2, and 58
- Language:
- Multiple languages
- Description:
- Current research on the effect of increased UV-B radiation on crop production has been limited to exposing plants to improbable UV-B dose or growth condition. The objective of this study was to test the effects of short-term modulated increased UV-B radiation on maize (Zea mays L.) growth, grain yield, and quality under field conditions for three years. A modulated irradiance system was used to maintain UV-B radiation at 30% above the ambient level and was applied daily between the elongation and silking stages of maize. The result indicated that increased UV-B radiation adversely affected maize growth and yield, especially on plant height when UV-B was enhanced at the elongation stage and on yield when UV-B was enhanced near the silking stage. Yield reduction that induced by enhanced UV-B radiation was associated with reductions in number of kernels per row and kernel mass. Protein content of grains was increased with enhanced UV-B radiation, but oil and starch contents were not affected. This study confirmed the sensitivity of maize to increased UV-B radiation under the field condition, and contributed to understand the full negative and positive effects of increased UV-B radiation on crop production., L. N. Yin, S. W. Wang., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
896. Modulation of substance P signaling by dipeptidyl peptidase-IV enzymatic activity in human glioma cell lines
- Creator:
- Petr Bušek, Jarmila Stremeňová, Evžen Křepela, and Aleksi Šedo
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Biochemie. Molekulární biologie. Biofyzika, fyziologie, gliomy, vápník, physiology, gliomas, calcium, dipeptidyl peptidase, substance P, NK1 receptor, calcium signaling, 2, and 577
- Language:
- English
- Description:
- Dipeptidyl peptidase-IV (DPP-IV, CD26) is a serine protease almost ubiquitously expressed on cell surface and present in body fluids. DPP-IV has been suggested to proteolytically modify a number of biologically active peptides including substance P (SP) and the chemokine stro mal cell derived factor-1α (SDF-1α, CXCL12). SP and SDF-1α have been implicated in the regulation of multiple biological processes and also induce responses that may be relevant for glioma progression. Both SP and SDF-1α are signaling through cell surface receptors and use intracellular calcium as a second messenger. The effect of DPP-IV on intracellular calcium mobilization mediated by SP and SDF- α was monitored in suspension of wild type U373 and DPP-IV transfected U373DPPIV glioma cells using indicator FURA-2. Nanomolar concentrations of SP triggered a transient dose dependent increase in intracellular calcium rendering the cells refractory to repeated stimulation, while SDF-1α had no measurable effect. SP signaling in DPP-IV overexpressing U373DPPIV cells was not substantially different from that in wild type cells. However, preincubation of SP with the DPP-IV overexpressing cells lead to the loss of its signaling potential, which could be prevented with DPP-IV inhibitors. Taken together, DPP-IV may proteolytically inactivate local mediators involved in gliomagenesis., P. Bušek, J, Stremeňová, E. Křepela, A. Šedo., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
897. Mokřadní louky Sedlčanska - střípky z krajin minulých
- Creator:
- Jiří Malíček
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Botanika, flóra, mokřadní ekosystémy, louky, mokřady, Sedlčany (Česko), 2, and 58
- Language:
- Czech
- Description:
- In contrast to the typical Central Bohemian landscape, the Sedlčany region is characterized by quite a high concentration of wet meadows; most of them discovered during the last few years. Though it is only a fragment of their original extent. Suitable management is absent at most localities, but a restoration of farming on selected meadows has recently been started. and J.Malíček.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
898. Molecular characteristics and expression patterns of Rubisco activase, novel alternative splicing variants in a heterophyllous aquatic plant, Sagittaria graminea
- Creator:
- Wang, D., Xie, S. Z., Yang, J., and Wang, Q. F.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, Alismataceae, aquatic photosynthesis, heterophylly, Sagittaria graminea, 2, and 581
- Language:
- Multiple languages
- Description:
- a1_Two full-length cDNAs (SGrca1 and SGrca2) encoding ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activase (RCA) were cloned from a heterophyllous aquatic plant, Sagittaria graminea, using Rapid-Amplification of cDNA Ends (RACE). SGrca1 contains a 1,320 bp open reading frame encoding a protein of 440 amino acids, and SGrca2 is exactly identical to SGrca1 except for 330 bp missing in the middle of SGrca1. Sequence analysis of cDNA and genomic DNA indicated both two cDNAs were generated from a common gene via alternative splicing. The deduced amino acid sequence encoded by SGrca1 showed 75-82% identity with other RCAs from higher plants and showed high homology in three highly conserved motifs associated with ATP-binding sites. RT-PCR analysis suggested both SGrca1 and SGrca2 were expressed in green tissues. During a 14 h light/10 h dark photoperiod, both aerial and submerged leaves exhibited the similar expression pattern of SGrca1 and SGrca2 with SGrca1 as the dominant form, but the accumulation of both SGrca1 and SGrca2 mRNA was significantly inhibited in the submerged leaves., a2_Western blot analysis showed that both SGrca1 and SGrca2 had their translation products, the 43 kDa form and the 31 kDa form expressing in leaves. Interestingly, the aerial leaves expressed higher amount of the 43 kDa form compared with the 31 kDa form, while it was reversed in the submerged leaves. The results demonstrated that both environments regulated the RCA gene expression at both transcriptional and posttranscriptional level. In addition, co-immunoprecipitation assay revealed that the isolated Rubisco-RCA complex contained both the 43 and 31 kDa forms, and the proportion of the 31 kDa form was obviously enhanced in the submerged leaves. The results indicated that both the 43 kDa and 31 kDa forms were involved in Rubisco and RCA interaction and the increased incorporation of the 31 kDa form was associated with submerged photosynthetic environment., D. Wang, S. Z. Xie, J. Yang, Q. F. Wang., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
899. Molecular characterization of 5-chlorophyll a/b-binding protein genes from Panax ginseng Meyer and their expression analysis during abiotic stresses
- Creator:
- Silva, J., Kim, Y. J., Sukweenadhi, J., Rahimi, S., Kwon, W. S., and Yang, D. C.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, gene expression, gene isolation, 2, and 581
- Language:
- Multiple languages
- Description:
- The chlorophyll a/b-binding protein (CAB) serves in both photosystems (PS), I and II, as a coordinator of antenna pigments in the light-harvesting complex (LHC). The CABs constitute abundant and important proteins in the thylakoid membrane of higher plants. In our study, five CAB genes, which contained full-length cDNA sequences from the 4-year-old ginseng leaves (Panax ginseng Meyer), were isolated and named PgCAB. Phylogenetic comparison of the members of the subfamily between ginseng and higher plants, including Arabidopsis, revealed that the putative functions of these ginseng CAB proteins were clustered into the different family of Arabidopsis CABs; two PgCABs in LHCII family and three PgCABs in LHCI family. The expression analysis of PgCABs consistently showed dark-dependent inhibition in leaves. Expression analysis during abiotic stress identified that PgCAB genes responded to heavy metal, salinity, chilling, and UV stresses differently, suggesting their specific function during photosynthesis. This is the first comprehensive study of the CAB gene family in P. ginseng., J. Silva, Y. J. Kim, J. Sukweenadhi, S. Rahimi, W. S. Kwon, D. C. Yang., and Seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
900. Molecular taxonomy of the Sympetrum vulgatum (Odonata: Libellulidae) complex in the West Palaearctic
- Creator:
- Hinojosa, Joan C., Martín, Ricard, Maynou, Xavier, and Vila, Roger
- Format:
- print, počítač, and online zdroj
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Zoologie, vážky, fylogeografie, Odonata, phylogeography, Libellulidae, Sympetrum vulgatum, molecular systematics, molecular taxonomy, mitochondrial DNA, nuclear DNA, 2, and 59
- Language:
- English
- Description:
- The Sympetrum vulgatum (Linnaeus, 1758) complex is composed of the subspecies S. vulgatum vulgatum, S. vulgatum decoloratum (Selys, 1884) and S. vulgatum ibericum Ocharan, 1985 in the West Palaearctic. These taxa have parapatric distributions and noticeable morphological differences in colour and body size, and their taxonomic status is debated. Here we revise the systematics of this group using molecular taxonomy, including molecular analyses of mitochondrial (cytochrome c oxidase subunit I, COI) and nuclear (internal transcribed spacer, ITS1) DNA taking into account known morphological differences. Each subspecies has a unique and differentiated COI haplotype, although divergences among them are low (0.4% maximum uncorrected p-distance). The subspecies are not differentiated by the nuclear marker ITS1. The genetic results for these taxa contrast with the deep divergence of the sister species S. striolatum (Charpentier, 1840). Given current evidence, we propose to maintain the subspecific status of the S. vulgatum complex and hypothesize their biogeographical history. It is likely that the three subspecies became isolated during one of the latest glacial periods, each in a different refugium: S. vulgatum ibericum possibly occupied the Iberian Peninsula, S. vulgatum vulgatum the Balkan Peninsula or territories further east and S. vulgatum decoloratum Anatolia., Joan C. Hinojosa, Ricard Martín, Xavier Maynou, Roger Vila., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public